Air conditioning means for enclosures



1953 G. A. BURGESS AIR CONDITIONING MEANS FOR ENCLOSURES Filed Aug. 26, 1950 lllllll III INVENTOR, Glenn A. Burgess ATTORNEY Patented Feb. 17, 1953 UNITED STATES PATENT OF F'I'CEI.

AIR CONDITIONING S F OR ENCLOSURES 15 Claims.

The present invention relates generally to air conditioning means for conditioning the air of an enclosure; and is concerned particularly with such means for cooling or refrigerating air for the cabin or other compartment of aircraft;

It is one object of the herein described invention to provide air conditioning means, wherein power means such as a cooling turbine maybe utilized for converting energy of the enclosure conditioning air into mechanical energy; and this recovered energy utilized to drive coolant air cinculating means which is connectedso as todischarge its output into an aspirator for creating a, suction on the downstream side of the coolant air path of a heat exchanger.

A further object is to provide a cooling system for an enclosure, wherein'a single heat exchanger of unitary construction may be utilized having a primary section and a secondary section, and in which power means driven" by enclosure conditioningair drives coolant air circulating means for one. section of the heat exchanger, and the discharge from the coolant air circulating means is conducted to an aspirator for aspiration of coolantair through the other section of theheat exchanger;

Another object is to provide air conditioning means in which the output discharge of an air circulating mechanism is utilized in a suitable device, such as an aspirator, for creating a sue-- tion. for the circulation of other air for a useful purpose, for example, the coolant air for a heat exchanger, and wherein the actuating air and aspiratedairleaving the aspirator are mixed and discharged through a single'duct rather than-a plurality of ducts.

Still another object is to provide in connection with air conditioning means embodying power driven air moving unit, such as a compressor unit, an aspirator in the compressor output for effecting circulation of other air, and which will at the same time serve as a load regulating device on the compressor unit.

Further objects of the invention will be brought out in the following part of the specification, wherein detailed'descriptionis for the: purpose of fully disclosing several embodiments of the invention without placing limitations thereon.

Referring to the accompanying drawings, which are for illustrative purposes only:

Fig. 1 is a view schematically illustrating cooling mechanism embodying the features of one form of the herein described invention;

Fig; 2 is a detail View diagrammatically illus-- trating the interconnection between the by-pass control: valves of. the present invention;

Fig. 3- is a similar view of amodified form-:of the invention; and

Fig, 4 is a I-ragmentary view showing a variation of the means for controlling the discharge now of cool-ant air irom theheatexcnangerr Referring now to the drawings, for purposes: of illustration several embodiments ofthe invention have been illustrated. In its broad concept, the invention may be utilized for the COIlflltlGIllIIgOf air for enclosures generally, but is particuiariy: useful for the conuitlomng or rei'rigeratlon; 0t air in the compartments of aircrari'i, which; may seof the pressurized or unpressurized type.

The embodimentdisclosed in Fig 1. is nlustrae tive-of an arrangement-Ira supplying GOIflClll/iOns i-ng air to a pressurized compartment iii: which may be the cabin of an aircrart. Thetconditinn ingair is supplied from a pressure an: sourcev I i to a heat exchanger I2' wherein. the-conditioning air is brought into-heat exchange. relation with a fluid coolantt Air is supplied from the pressureairlsouroes 12E to-the heat exchanger Iii through a: duct: til through: which the: flow of air may becontrolled and regulated by sensing responsive devices (not shown): depending upon the desigmrequirements of the compartment of the airplane;

The heat exchanger l2is illustrated asa single unitihaving a-primary section ld andasecondary section 1-5; The conditioning air: flows through the primary section in a single pass, but. istcone ducted through. atsecond'arysection; in a double pass; The conditioning; air: discharge from: the heat exchanger i connected through a .ductu Hi with the inlet. of energy: convertingmeans: I! which in this: instance comprises an. expansion turbinewhichacts to further cool' the conditions ing air and convert energy or the-conditioning air into mechanical energy: for powenor other. useful purpose. The outlet oi'thezenergycone verti'ng means: H isconnected-with thcxcompartment. l0. 7

Coolant. fluid: is supplied: to the: heat, exchanger from at suitable source; which in. thispinstance: illustrated as: comprising'a ram duct, 18'.- whien is connected with the.- coolant. inlet'side of: theiprie mary section: l4 and: secondary section. iii of: the heat exchanger.

The: outlet side for; coolant: of. the secondary section of the heat exchanger connects: withthe inlet of air moving; means t9, in-thisiinstance a fan having its impeller directly connected; for drive. from the energy converting means; klflby means of a, transmission'shaft. 2,0. 7

The outlet, from the air movinggmeans is di' rected through a discharge. duct- 211;

efiect forms the nozzle of an aspirator, as generally indicated by the numeral 22, the discharge duct being surrounded by a concentrically positioned mixer duct 23. The inlet end of the mixer duct is connected to receive the discharge of coolant fluid from the primary section I4 of the heat exchanger, and the outer end of the mixer duct is carried to a discharge point where the coolant fluid is discharged overboard or otherwise disposed of.

Reverse flow of coolant fluid through the primary section M of the heat exchanger i prevented under certain conditions of operation by means of a check valve 24 which is mounted in the connection of the coolant discharge of the primary section 14 with the aspirator. Primarily, the check valve 24 provides means for blocking the primary heat exchanger coolant passage when the air conditioning means is operated on the ground, in which case the ram duct I8 is ineffective V Means are provided for controlling the temperature of the conditioning air in accordance with the temperature variations of the compartment [0. This is accomplished through the utilization of a plurality of controlled by-pass ducts. As shown in Fig. 1, one of these ducts, as indicated by the numeral 25, is connected at its inlet end with duct l3 upstream from the heat exchanger l2, and at its outlet end with a duct 26 which connects the outlet of the energy converting means I! with the compartment I0. The duct 25 therefore by-passes the heat exchanger and energy converting means so as to conduct conditioning air of relatively higher temperature to the compartment.

The other by-pass duct, as indicated by the numeral 21, is connected around the energy converting means I] only, the inlet end of the bypass duct 21 being connected to the duct I6 and the outlet end being connected to the duct 26. In some installations, it may be found desirable to leave out one or .the other of the ducts 25 and21. v v 7 Flow control through the ducts 25 and 21 is controlled by means of a pair of butterfly valves Hand 29, mounted respectively in the by-pass ducts 25 and 21. These valves are actuated by a common torque actuator 30, the direction of which is controlled through circuit connections 3| and 32 which are selectively energized by a temperature sensing device 33 in the compartment [0.

. The valves 28 and 29 are arranged to proportionally contro1 the flow of air through the bypass ducts, and are usually arranged with a predetermined angular lag inthe time of full closing of one valve with respect to the time of closing of the other valve.

In the arrangement described herein, the valve 29 is arranged to open prior to th opening of valve 28. This is accomplished by having one of the valves coupled directly to the actuator, and providing a lost motion connection with the other valve. Such a connection is diagrammatically illustrated in Fig. 2, wherein the valve 29 is shown as being directly connected with an acloading spring 31'normally biasesthe valve 28 4 towards an angular position with respect to the valve 29. With this arrangement, it will be apparent that with both valves in closed position, the valve 28 will remain closed until the valve 29 has been moved in an opening direction through an angle of substantially It will be appreciated that the angular relationship between the valves 28 and 29, need not be limited to 45 but may be made some other angle if desired. Moreover, the connection may be arranged so that the angular displacement between the opening and closing of the valves may be adjustable.

In the arrangement described above, the air moving means l9 comprises a low head compressor or fan, and the operation of the aspirator 22 may vary depending upon the conditions of operation. For example, under no-ram or lowram condition of operation, a pressure adjacent the discharge end of duct 2| slightly in excess of pressure existing at the coolant inlet to the primary section of the heat exchanger will cause the aspirator to function as such. Thus, the operation willbe somewhat difierent in diiferent installations due to duct losses, etc.

Under high-ram conditions, wherein the pressure at the coolant inlet of the primary section of the heat exchanger is much higher than the pressure adjacent the discharge end of the duct 2|, the aspirator functions more as a mixer than as a true aspirator.

The conditioning means described above is advantageous in that it permits use of a turbinefan assembly of smaller weight, height and size than that which would ordinarily be required, so

that where the conditioning means is provided as a refrigerating package, the material size physically of the package is reduced. Moreover, the utilization of an aspirator as explained above 1 permits building a multi-section primary and secondary heat exchanger as a single unit utilizing one discharge duct.

Referring to Fig. 3, the arrangement disclosed therein is primarily a simple system embodying the features of the invention, and while considered herein primarily for the supplying of conditioning air to an unpressurized compartment or enclosure, it is not limited to this particular use, and may under proper conditions be utilized for pressurized enclosures. Similar parts, corre- L sponding to the parts of the arrangement shown in Fig. 1, have been given the same indicating numeral.

The arrangement of Fig. 3 differs basically from that shown in Fig. 1, in that the air moving means I9 in this case has its intake supplied directly from the ram duct 18 through a supply duct 38, and has been illustrated as a true compressor. The outlet of the air moving means [9. is connected through an outlet duct 39 to the discharge duct 2| which in this case comprises the nozzle of the aspirator.

It will be appreciated that the aspirator can connected with the outermixer duct oftheaspir-tator and allows adequate flow ofcoolant under no-ram conditions, yet functionsv to restrict flow under high-ram conditions so as to prevent excessive flow of coolant air and thus minimize undesirable drag on the aircraft.

Instead of utilizing a venturi, as shown in Fig. 3'for automatically controlling the flow. of coolant through the heat exchanger 12, the coolant now may be controlled by a valve, such as indicated in Fig. 4 by the numeral this valve being actuatable by a. torque actuator d2 which is selectively operable through a circuit 43 by means of a control switch M. The control switch :34 may form a part of a control device arranged for thermostatic actuation, pneumatic actuation or other suitable means. If desired, the valve M may be manually operated. By utilizing a valve instead of a venturi, the coolant drag is minimized, since a greater flow restriction is possible under high-ram conditions without exceeding the low heads which can be developed by the aspirator under no-ram conditions.

The utilization of an aspirator 22, as described in the arrangement disclosed in Fig. 3, provides the additional advantageof regulating the speed of the turbo-compressor unit. Should the turbine tend to increase its speed, this increased speed will cause the compressor to build up pressure in the aspirator nozzle, and as a result additionally loads the turbine and prevents overspeeding. Conversely, should the turbine tend to slow down, the pressure in the aspirator nozzle is correspondingly reduced so that the load on the turbine is decreased, whereupon the decrease in turbine speed will be minimized. It will therefore be seen that the aspirator additionally functions to regulate the speed of the turbo-compressor unit.

I claim:

1. Air conditioning means for an enclosur', comprising: a flow path for conducting conditioning air to said enclosure; means in said path for bringing the conditioning air into heat exchange relation with a coolant; means for converting energy of the conditioning air into mechanical energy; air circulating means driven by said energy converting means; means actuated by air from the air circulating means for inducing flow of said coolant; a by-pass duct for flow of conditioning air around the heat exchange means and the energy converting means; aseparate by-pass around the energy converting means; and valve means for proportionally controlling the air flow in said by-passes in response to temperature variations within said enclosure.

2. Air conditioning means for an enclosure, comprising: a flow, path for conducting conditioning air to said enclosure; means in said path for bringing the conditioning air into heat exchange relation with a coolant; means for converting energy ofthe conditioning air into mechanical energy; air circulating means driven by said energy converting means; means actuated by air from the air circulating means for inducing flow of said coolant; a by-pass duct for flow of conditioning air around the heat exchange means and the energy converting means; a separate by-pass around the energy converting means; and means for controlling the air flow in said by-passes in response to an air conditioning requirement of said enclosure.

3. Air conditioning means for an enclosure, comprising: a flow path for conducting conditioning air to said enclosure; a heat exchanger in said flow path having a single pass primary said conditioning air; aturbinein: said flow Bath:

downstream from said heat exchanger: a fandriven by said turbine; concentric inner and outer tubular members forming an aspirator and, mixing duct; a ram sourceof coolant aimbranch. ducts from said source, one of said branch ducts. being connected through said secondary section and said fan to. said inner tubular members; and: the other branch duct being connected through said primary. section to said outer tubular moms bar; and a. check valve in said latter branchs duct, between said primary section and the outer. tubu, lar member operable to closed position upon, a. predetermined reduction of flow 4. Air conditioning means. for an enclosure; comprising: a flow path for conducting condi-r tioning air to said enclosure; a heat exchanger in said flow path having a primary section and a secondary section; a turbine in said flow path downstream from said heat exchanger; a fan driven by said turbine; concentric inner and outer tubular members forming an aspiratorand mixing duct; a ram source of coolantair; branch. ducts from said source, one of said ducts being connected through said secondary section and? said fan to said inner tubular member, and the other branch duct being connected through said primary section to said outer tubular member; and a check valve in said latter branch duct be-i tween said primary section and the outer tubular member operable to closed position. upon a pre-\ determined reduction of flow.

5. Air conditioning means for an enclosure, comprising: a flow path for conducting: condii-w. tioning air to said enclosure; a heat exchanger in said flow path; a turbine in said flow path downstream from said heat exchanger; a compressor driven by said turbine; anaspirator hav ing a nozzle for primary air and a suction connection; a ram source of coolant air; branch ducts from said coolant air source, one of said ducts being connected through said compressor to said nozzle, and the other of said ducts-being: connected through said heat exchanger-to: said suction connection, whereby coolant air is sucked through the heat exchanger in heat exchange relation to the enclosure conditioning air; and

a venturi in said latter branch duct between the heat exchanger and aspirator suction connection.

6. Air conditioning means for an enclosure, comprising: a flow path for conducting conditioning air to said enclosure; a heat exchanger in said flow path; a turbinein said flow path, downstream from said heat exchanger; a com,- pressor driven by said turbine; an"aspirator-having a nozzle for primary air and a suction connection; a ram source of coolant air; branch ducts from said coolant air source, one of said ducts being connected through said compressor to said nozzle, and the other of said'ductsbeing' connected through said heat exchanger to said suction connection, whereby coolant air is sucked through the heat exchanger in heat exchange relation to the enclosure conditioning air; and means in said latter branch duct between the heat exchanger and aspirator suction connection for varying flow therein.

7. Air conditioning means for an enclosure, comprising: a flow path for conducting conditioning air to said enclosure; a heat exchanger in said flow path; a turbine in said flow path downstream from said heat exchanger; a compressor driven by said turbine; an aspirator having anozzle .for primary air and a suction connection; a ram source of coolant air; and branch ducts from said coolant air source, one of said ducts being connected through said compressor to said nozzle, and the other of said ducts being connected through said heat exchanger to said suction connection, whereby coolant air is sucked through the heat exchanger in heat exchange relation to the enclosure conditioning air.

.8. Air conditioning means for an enclosure, comprising: a flow path for conducting conditioning air to said enclosure; a heat exchanger in said flow path; a turbine in said flow path downstream from said heat exchanger; a compressor driven by said turbine; an aspirator having a. nozzle for primary air and a suction connection; a source of coolant air; and branch ducts from said coolant air source, one of said ducts being connected through said compressor to said nozzle, and the other of said ducts being connected through said heat exchanger to said suction connection, whereby coolant air is sucked through'the heat exchanger in heat exchange relation to the enclosure conditioning air.

9. Air conditioning means for an enclosure comprising: a flow path for conducting conditioning air to said enclosure; a heat exchanger for bringingv the conditioning air into heat exchange relation with air from a coolant air source; a cooling turbine in the conditioning air flow path; an air moving device driven by said turbine having an inlet connection with the coolant air'source and an outlet connection with a discharge duct; and a concentrically spaced duct surrounding the discharge end of said discharge duct and having an inlet flow connection with said coolant air source including said heat exchanger, whereby air discharge from the discharge duct is mixed with coolant air from the heat exchanger,

10. Air conditioning means for an enclosur comprising: a flow path for conducting conditioning air to said enclosure; means in said path for bringing the conditioning air into heat exchange relation with a coolant; means for converting energy of the conditioning air into mechanical energy; air circulating means driven by said energy converting means; and an aspirator having a nozzle connected to receive air from the air circulating means, and a suction connection with said heat exchange means for inducing flow of said coolant therethrough.

11. Air conditioning means for an enclosure, comprising: a flow path for conducting conditioning air to said enclosure; means in said path for bringing the conditioning air into heat exchange relation 'with a coolant; means for convertingenergy of the conditioning air into me-' chanical energy; air circulatin means driven by said energy converting means; and means actu ated by air from the air circulating means for inducing flow of said coolant.

comprising: a fiowpath for conducting condi-;

tioning air to said enclosure; heat exchange means for bringing the conditioning air into heat exchange relation with a coolant; means for converting energy of the conditioning air into mechanical energy; and means actuated by said energy converting means for circulating said coolant through the heat exchanger, said circulating means including means for regulating the load imposed on said energy converting means.

13. Air conditioning means for an enclosure, comprising: a flow path for conducting conditioning air to said enclosure; heat exchange means for bringing the conditioning air into heat exchange relation with a coolant; means for converting energy of the conditioning air into mechanical energy; and means actuated by said energy converting means for circulating said coolant through the heat exchanger, including means for regulating the load on said energy convert-- ing means in response to speed variations.

14. Air conditioning means for an enclosure, comprising: a flow path for conducting conditioning air to said enclosure; means in said path for bringing the conditioning air into heat exchange relation with a coolant; means for converting energy of the conditioning air into mechanical energy; air circulating means driven by said energy converting means; and aspirator means actuated by air from said air circulating means for inducing flow of said coolant and regulating the speed of said energy converting means.

15. Air conditioning means for an enclosure, comprising: a flow path for conducting conditioning air to said enclosure; means in said path for bringing the conditioning air into heat exchange relation with a coolant; a coolant source; an aspirator having a nozzle connection and a suction connection respectively with said coolant source, said suction connection including said heat exchanger means; and means driven by conditioning air for circulating coolant air through said nozzle, whereby coolant flow is induced through said heat exchanger means.

GLENN A. BURGESS.

REFERENCES CITED The following references are of record in the file or" this patent:

UNITED STATES PATENTS I OTHER REFERENCES Refrigeration for Air Conditioning Pressurized Transport Aircraft by Bernard L. Messinger, in SAE Journal (Transactions) 3, March 1946; pp, 93406.

, volume 54, Number 

